<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title></title>
	<style>
		#container{
			display:flex;
			float:left;
			margin-left:10px;
		}
		#container button{
			display:block;
			border:1px solid red;
			width:100px;
			height:50px;
			font-size:30px;
			border-left:none;
		}
		#container button:first-child{
			border-radius:5px 0 0 5px;
			border-left:1px solid red;
		}
		#container button:last-child{
			border-radius:0 5px 5px 0;			
		}
	</style>
	<script>
		window.onload=function(){
			var container=document.getElementById('container');
		}
	</script>
</head>
<body>
	<div id="container">
		<button>1</button>
		<button>2</button>
		<button>3</button>
		<button>4</button>
	</div>
	<div id="container">
		<button>5</button>
		<button>6</button>
		<button>7</button>
	</div>
	<div id="container">
		<button id="last">8</button>
	</div>
</body>
</html>